The invention relates to a connection insert and more specifically to a connection insert with adhesive supply channel.
This connection insert is used for the fastening of components to boards, these boards generally having a soft inner core and hard cover boards. These boards are generally called lightweight boards. The connection insert is provided with a central adhesive supply channel and with outlets for the adhesive which are perpendicular to the channel. In a construction, the above-mentioned board-shaped components are used, among other uses, for the production of furniture. The connection inserts are used for guiding the adhesive such that it reaches the connection inserts and the latter form a fixed connection with the fixed regions of the boards. However, it is also conceivable that the end regions of the connection inserts are inserted into boreholes or recesses of the board-shaped components so that they support the adhesive connection.
It is a disadvantage of the previously known connection inserts that the guiding of the adhesive is not precisely defined, so that it frequently happens that the adhesive does not arrive at the point where the actual adhesive connection is to take place. However, a precise guidance is required because adhesives are considered to be semi-fluidic; that is, their viscosity is relatively high.
It is an object of the disclosure to design a connection insert of the initially described type such that a precise guidance of the injected adhesive is ensured, so that the adhesive connections take place at the defined locations.
This object is achieved in that the connection insert consists of a plurality of parts and comprises an inner part having the adhesive supply channel and an outer sleeve enveloping the inner part.
The adhesive is placed in the connection insert by means of a suitable device from a front side. The outside surface of the inner part and the inside surface of the outer sleeve may be designed such that a targeted adhesive guidance is feasible. In particular, depending on the usage of the connection insert, the outer sleeve can be designed such that targeted adhesive connections are achieved. Since it causes the distribution of the adhesive, it could also be called a distributor sleeve or an adhesive guiding sleeve.
In the simplest construction, the connection insert consists exclusively of the inner part and the outer sleeve. An annular gap is arranged between the inside surface of the outer sleeve and the outside surface of the inner part.
For reinforcing the adhesive connection between the connection insert and the adjacent component, for example, to a board, the inner part has a head at least at one end, which head can at least partially form-lockingly and/or force-lockingly be inserted in a borehole or in a recess of the component. The connection of the head of the inner part with the component can take place in a particularly simple manner. The circumferential surface of the head is profiled such that the raised parts mold themselves into the material bounding the borehole or the recess. This becomes possible because the concerned components consist of wood or a wood-like material. The profiling of the circumferential surface can be formed by harpoon-type webs, so that the inner part can be pressed in one direction into the borehole or into the recess, but that a pulling-out in the opposite direction is possible only by destroying the material parts bounding the borehole or the recess. The mutually spaced harpoon-type webs may be shaped in a surrounding manner to the head of the inner part; they may also extend over certain partial regions of the circumference; or the may extend in the direction of the longitudinal center axis of the inner part, so that an antitwist protection is correspondingly provided in the last embodiment.
For gluing the head of the inner part to the surfaces bounding the borehole or the recess, the head of the inner part is equipped with at least one, for example two diametrically opposite adhesive outlet opening(s). The adhesive outlet opening or openings is/are expediently designed in a slot shape as well as extending in the direction of the longitudinal axis of the inner part.
In order to also permit the gluing-together over the entire length of the shaft of the inner part, the inner part has several mutually spaced circumferential grooves on the circumferential surface. So that adhesive can also penetrate into these circumferential grooves, the inner part outside the head has at least one adhesive outlet opening, preferably with two mutually diametrically opposite adhesive outlet openings. Through each adhesive outlet opening, the adhesive can then arrive in the annular gap between the outside surface of the inner part and the inside surface of the outer sleeve. So that the adhesive can also arrive in the end regions of the shaft of the inner part, each adhesive outlet opening is arranged in the central region of the shaft.
The adhesive can be pressed into the adhesive supply channel of the inner part only from a front side. So that the quantity of the adhesive remaining in this channel is limited, the adhesive supply channel is divided into two sections, and that only one section extends into the region of the adhesive outlet openings. For securing the outer sleeve, the inner part is equipped with a locking ring on the side facing away from the head. The locking ring is designed such that such a deformation takes place as a result of the effect of a compression force. Thus, the outer sleeve can be placed upside down onto the inner part. In addition, a lateral distribution of the adhesive takes place. So that the adhesive can be distributed over the entire length or height of the shaft of the inner part and also over the inside surface of the outer part, the inside surface of the outer sleeve is constructed as a profiling which is formed of indentations and elevations extending in the longitudinal direction. In other words, the elevations and indentations extend transversely to the circumferential grooves of the shaft of the inner part.
In addition, in the end region facing the head of the inner part, the outer sleeve is provided with several slots in order to facilitate the joining or the snapping-together of the inner part with the outer sleeve. Furthermore, when adhesive is supplied, the latter emerges from the slots, which has a positive influence on the adhesive connection.
The adhesive supply normally takes place under pressure. Particularly the outer sleeve could be called an adhesive guiding element so that the adhesive is pressed into the end regions in a targeted manner. After a reduction of the supply pressure, the adhesive could flow back into the central region of the outer sleeve. In order to prevent this, the outer sleeve is equipped with flexible retaining elements for the adhesive on the outside surface at least in the end regions. These retaining elements are designed such that they form a corresponding abutment. The retaining elements may be arranged in different fashions. Thus, they extend radially or tangentially with respect to the outside surface of the outer sleeve in the end regions facing the outside surface of the outer sleeve. Although it is sufficient for the retaining elements to be arranged in the end regions, in another embodiment, they are arranged radially with respect to the longitudinal center axis of the outer sleeve and extend over the entire length or almost the entire length of the outer sleeve. In this case, the lengths of the retaining elements increase from the center region to the end regions of the outer sleeve, for example in a continuous manner. As a result, analogously an outer contour is created relative to the longitudinal section, which can be considered to be concave. The retaining elements are expediently constructed as bristles, strips or the like.
It is also provided that the adhesive supply channel has a sieve or a perforated plate in the end region. This proportions the adhesive quantity and prevents that impurities penetrate into the adhesive supply channel. Depending on the usage, it may also be expedient to provide the outer sleeve with several openings, which are circular or have a configuration deviating from the circular shape.
The range of applications of the connection insert is diverse. Thus, the outer and the inner part each have a cup-shaped construction, and the connection insert can be fixed to a furniture component or a furniture leaf by generally known eccentric fitting.
The connection insert may be called a dowel in order to fasten fittings or the like, for example, by a screw.
The connection insert will be explained in greater detail by means of the attached drawings.